Itching to install my new exhaust - Question(s)

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HyperPete

HyperPete

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Location
Adams County, PA
Greetings!

I already know the correct way to do this, but I'd like input on the INCORRECT way.

I just received my new to me Kerker 4-2-1 exhaust for my '99. I am itching to install it BEFORE I get the jets for it. I have an untrimmed K&N filter in the stock airbox. The previous owner installed stage 1 jets.

How likely am I to run lean enough to cause damage if I install the Kerker before I get the new jets and install them? Presently I have SuperTrapp slip-ons and it's running a little rich, but overall quite well.

I KNOW that the right way to set it up will include bigger jets, and I **AM** going to install them (or have them installed.) I just want to play with my new "toy" ASAP. Is this a very bad bad idea, or is the K&N and stock airbox restrictive enough that it will be OK for now? (Darn, I wish it were fuel injected!!!)

Thanks in advance!
 
Check out this thread. I asked almost the very same question. Bottom line....if you have an aftermarket exhaust system on the bike.....you flow more "air" out of the engine....so you flow more "air" into the engine....right? Flowing more "air" into the engine....will pull MORE fuel. With an aftermarket exhaust...you will have to LEAN out the jets. Stage 1 jets are probably the DJ's.....and I am assuming DJ 165's. That is the equivalent of BETWEEN the stock MK 152.5's and 155's, so you are already running a bit richer than the stock 152.5's.

http://www.vmaxforum.net/showthread.php?t=25903

After my Kerker 4-1....I got the best HP with MK 150's. OH!!! its really hard to get a Vmax too lean....if it is too lean it just wont pull in the upper RPM's.
 
Dynos near me are pretty expensive. I will need to plant more money trees if I plan on dynoing the bike! I may have to rely on the old BUTT dyno, and plug readings.
 
Are there any Vmaxxers near you that could help and possibly loan a sync tool if needed?
 
Too lean, good one Hyper!
You are gonna love the new exhaust and I don't even know what you are coming from. Hope you got the Competition baffle for it. You are gonna fall in love with it all full song! Even my neighbor likes it especially when I back out of the throttle before turning onto our street.
 
Yep, I have the competition baffle for it. I just put that in. Repainting the headers today and then I guess I will install the exhaust tomorrow. I guess I am gonna have some Supertrapp Slip-ons for sale now too.
 
PATMAX said:
Too lean, good one Hyper!
You are gonna love the new exhaust and I don't even know what you are coming from. Hope you got the Competition baffle for it. You are gonna fall in love with it all full song! Even my neighbor likes it especially when I back out of the throttle before turning onto our street.
Click to expand...

Yes beautiful music!

I used love approaching a bike night at a good clip and then downshifting through the gears......would try to kick down to the next gear at about 4000-4500 rpm, that sounded best. It's a lot of of fun watching 100 heads swivel to see what's coming! :eusa_dance:
 
As Trama posted you have the incorrect theory on what to do with a new exhaust system. We used to do the same thing ourselves but learned long ago that the conventional thoughts are wrong. There are a lot of factors to look at when determining what will happen but in short these bikes will want smaller mains when you free up the exhaust flow (and maintain or improve scavenging).

You cant' lean these up enough to hurt the bike unless running nitrous, supercharger, or turbo. Too lean on the natural aspiration will just not let it run.

Sean
 
HOLY AWESOMENESS! The new exhaust is SWEET!!! Not only does it sound wicked, but now i smokes the tire when I roll on the throttle! I only ran it around the block, gonna go wash up and take her out for a longer ride!
I guess I had better order a new back tire too so I have it ready, it will likely need it soon!

I also removed the Y from the top of the air box, and I see the previous owner had already trimmed the K&N.

OK, so, the bike is going to run rich until I re-jet it. Will it be rich enough to cause problems for a month or two? (IE Wash the oil off the cylinder walls and dilute the oil?)

Thanks to everyone for your responses!
 
In my opinion no....it wont run THAT rich. For it to run that rich, it will foul a plug first....and give you a heads up.

Glad that your enjoying yourself. So.....you like the kerker with the 2.5 inch baffle?
 
Good!....I think a Kerker sounds better in person then it does on Youtube videos.

I believe your in the right forum to be able to get more HP out of a Vmax.
 
Well, I rode the VMax to work today. That Kerker with the 2 1/2" competition baffle is just too loud with no packing! I am going to stop at CycleGear on my way home and get fiberglass packing for it. Hopefully that will resolve the matter.
 
I too was a little nervous about the jetting with my new exhaust. I changed from stock to UFO 4-1 drag. I know it's running rich, but it still runs like a rabbit on rockstar...Hopefully I get to do the jetting this spring.
 
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